Computational analysis of the effect of the control model of intraaorta pump on ventricular unloading and vessel response.

The intraaorta pump is a novel left ventricular assist device (LVAD) whose hemodynamic effects on the circulatory system is unknown. This article aims to evaluate the different effects on the circulatory system supported by the intraaorta pump. In this article, the pump is controlled by three control strategies, including the continuous flow method, the constant rotational speed, and the constant pressure head. A cardiovascular pump system, which includes cardiovascular circulation, intraaorta pump, and regulating mechanisms of systemic circulation, has been proposed. Left ventricle pressure (LVP), end-diastolic volume (EDV), and left ventricular external work (LVEW) were used to evaluate the degree of ventricular unloading. The pulsatile index (PI), which is defined as a ratio of pulse pressure and mean arterial pressure (MAP), was used to evaluate the effect of the vessel response by three control strategies. The comparison results showed that LVP and EDV were lower than those measured before the intraaorta pump was implanted. For LVEW, the constant pressure head strategy provided a superior ventricular unloading compared with other strategies. Support of the pump led to the lower pulsatility by the three models. However, the PI of the constant pressure head was the most at 0.37. In conclusion, these results indicate that the intraaorta pump controlled by constant pressure head strategy provides superior ventricular unloading and pulsatility of the vessel.